[svn-r28905] Purpose: Fix user reported problem

Description:
    User Adam Rosenberger reported a failure when using the member function
    AbstractDs::getArrayType().  This problem was caused by missing
    initialization of the ArrayType's members in some cases.
Solution:
    - Added ArrayType::setArrayInfo() to retrieve rank and dimensions of
      an array and store them in memory for easy access.
    - Re-factored a few functions to use the new function.
    - We'll give him 1.8.16 patch
Platforms tested:
    Linux/32 2.6 (jam)
    Linux/64 (platypus)
    Darwin (osx1010test)

c++/src/H5AbstractDs.cpp

@@ -141,8 +141,11 @@ ArrayType AbstractDs::getArrayType() const
    // depending on which object invokes getArrayType.  Then, create and
    // return the ArrayType object
    try {
+	// Create ArrayType and set values this way to work around the
+	// problem described in the JIRA issue HDFFV-7947
 	ArrayType arraytype;
 	f_DataType_setId(&arraytype, p_get_type());
+	arraytype.setArrayInfo();
 	return(arraytype);
    }
    catch (DataSetIException E) {